Apparatus for the production of high-frequency currents of electricity.



McCAA. APPARATUS FOR THE PRUDUCTION OF HIGH FREQUENCY CURRENTS 0FELECTRICITY.

APPLICATION FILED JAN.14| I914.

PatentedNov. 20, 1917.

Sowiny A connechbn. 0 arma Show L) DAVID G. MGCAA, LANCASTER,PENNSYLVANIA.

APPARATUS FOR THE PRODUCTION OF HIGH-FREQUENCY CUBEENTS OF EIiECTRICITY.

I Specification of Letters Patent.

Patented Nov. 20, 191?.

Application filed January 14, 1914. Serial No. 812,051. V

To all whom it may concern:

Be it known that I, DAVIDG. MGQAA, a citizen of the United States,residing at Lancaster, in the county of Lancaster and Stateof'Pennsylvania, have invented certain new and usefullmprovements inApparatus for the Product-ion of High-Frequency Currents of Electricity,of which the following is a specification.

I My present invention has for its object the provision of continuoushigh frequency currents of electricity, .which, while applicable for useto very many of the arts commonly employed at the present time, is yetmore particularly designed for and adapted to be employed in connectionwith systems which have for their especial purpose, the transmission ofsignals,radiotelegraphy,-and

of spokenspeech,radiotelephony,between points,'or' stations located at.distances, often great, from each other, without the employment ofconductors of electricity of any ma-' terial whatsoever, other thanatmospheric air, and to such end the invention contemplates, among otherends, the provision of means whereby an ordinary pulsatory current, oflow frequency and low electro-motive force, is changed, or transformedinto a current of high frequency oscillations and high electromotiveforce, to the attainment of which end the invention consists, in theconstruction, arrangement and combination of the several parts comprisedtherein for service and the operation of the same to'the end named,substantially as is hereinafter described and illustrated in theaccompanying drawings, wherein Figure 1, illustrates in a diagrammaticView, an electric circuit comprising in a single operating system, acurrent generating circuit, a current transforming circuit and a currenttransmitting circuit, each thereof including devices peculiar to thecircuit of which they are a part, and all connected and arranged inaccordance with my invention.

Fig. 2, illustrates in a simple cliagran1- matic view, the armaturewindings of the generator preferably employed in the present embodimentof my invention.

- Fig. 3, is a like diagrammatic view, illustratingthe manner in whichthe step up transformer primaries are connected in the presentembodiment of my invention.

Fig. 4, shows, in adiagiammatic view, the position, as regardseachother, of the primaries of the step up transformers employed in myinvention, and the manner in which said primaries are traversed by athree phase current from the generator.

Fig. 5, shows in side elevation, the current interrupting device whichoperates, within the spark gap included in the circuit between thesecondaries of the stepup transformers and primary of the air coretransformer, to interrupt and break up current crossing said gap, in theform of sparks.

' Fig. 6, is a top plan view of the interrupting device illustrated inFig. 5.

Fig, 7, shows, in a detail plan view, a portion of the interruptingdevice illustrated in Fig. 5, interposed between a pair of multiplepoint electrodes, and the interrupted sparks as they appear when the.device is in action.

Fig. 8, illustrates in ,a detail plan view, a portion of each of aplurality of interrupting devices, located between multiple pointelectrodes, and moving in opposite direc-.

tions, said view showing the interrupted sparks, as they appear when thedevice is in action.

.Fig. 9, illustrates in a detached detail view, a part of theinterrupting device, in full size.

Fig. 10, shows in a detached detail view, a part of an interruptingdevice similar in form to that shown in Fig. 9, but adapted to morerapidly break up current crossing the spark gap.

- Figs. 11, to 13, inclusive, illustrate different types of air corecoils which may be em ployed inmy invention, and

Fig. 14, shows a modification of the oscillatory circuit and theconnection of the same with the transmitting circuit.

The invention which forms the subject of the present application forLetters Patent, is, in the main, identical with that which formed thesubject of an application filed by me on the 27th of January 1911,numbered 605,054, and abandoned October 3rd 1912, and said presentapplication, or invention, inv commonqvith that set forth in theabandoned application referred to, contemplates the provision of means,whereby an ordinary pulsatory, that is to say, an alternating, currentof electricity, of low electro-motive force, is changed, or transformed,into a current of high frequency oscillations, of lngh electro-motiveforce, for

use in connection with radiotelegraphic and.

nadiotele'phonic systems, for the transmission of signals and of spokenspeech, he-

tween stations separated by a greater, or a less degree of space,without the employment of conductors, of any material whatsoever otherthan the natural media.

To the attainment of the end above named,

- many inventions 'havebeen made, each thereof employing as the mainagent to the. accomplishment of the purpose noted, some device eithermechanical, or otherwise, possessing qualifications necessary to bringabout the interruption of the current of e'lecf tr1c1ty at some polntbetween the source of surh current, and the point at which it isimpressed upon the transmiting; devices,. .WlllCll it 18 to energlze.

It is to be understood that the successful operation of the inventionsnoted, to the ends sought thereby depends wholly upon the extent towhich the'current has been broken up, or interrupted between the pointsReferring to the drawings. wherein simi--.

lar letters and numerals of reference denote similar parts, A,designates that part of my present invention which may be termed thecurrent generating, or primary clrcuit, B, that part which may be termedthe current transforming, or secondary circuit and C,

named, are interdependent upon each other that part which may be .termedthe trans-.

mitting, or sonorous circuit, and it is to be understood that theseveral circuits above to the end that the purpose of the invention .maybe realized.

7 In carrying my present invention into practice, I preferably employ athree phase generator D, that is to say. a generator having threewindings upon its armature, each thereof distinct and independent of theother and each adapted todeliver a current of electricity over acircuit'peculiar to itself, and I arrange that said windings, for thepurposes of said present invention, shall be placed upon the armature ofthe generator D, in accordance with the A scheme of connection, asindicated in Fig. 2.

' I employ, in connection with the generator D, three independent stepup transformers E, F and (Sr, preferably using the Y scheme inconnecting the respective primaries 1, 2 and 3, of said transformers,

through suitable c'ondutors 4:, 5 and 6,'with .the armature phase rings7, 8 and 9.

1 I provide the conductors 1, 5 and 6, between the generator D, and thetransforme'rsE, F and G, with'a three pole switch 10, to simultaneouslyclose circuit, through said conductors, between said generator andtransformers.

The several devices and connections therebetween' as last abovedescribed, constitute the current generating, or primary circuit A,.hereinbefore referred to and the opera-' *tion of said devices, aswellas the result of such operation upon the remaining elements comprised inmy invention, will be presently explained.

Having described the several devices which are comprised in thegenerating, or

primary circuit A, I will now proceed to describe those which arecomprised in the current transforming or secondary circuit B, whichcircuit includes, as the source of energy the secondaries-11, 12 and onepole of each of which, is connected to a conductor 14, which extendsthence to one pole of the primary 15, of, an air .core transformer H. y

I connect the opposite pole ofthe primary 15, through a common lead, orconductoi: 16, with three independent conductors 17, 18 and 19, andprovide said conductors, at their free ends, with the inductance coils20, 21 and 22, and from said coils I extend conductors 23, 24c and 25,which terminate in multiplepoint electrodes 26, 27 and 28, that arearranged in a common plane, see Fig. 1. v

I provide the poles of the secondaries 11, 12 and l3,'which are oppositethose connected to the common'conductor 1 1, with conductors 29, 30 and31, which terminate in multiple point electrodes 32, 33 and 34;, thatare arranged in a common plane opposite to and at a short distance fromthe multiple point electrodes 26, 27 and 28, see Fig. 1.

I provide each of the conductors 29, 30

and 31, with a condenser 35,36 and 37, re

spectively, arranging each thereof, in series with the gap formed in thecircuit of which each conductor is a part.

,It is to be understood that the space be tween each of the opposingmultiple point electrodes, forms the spark gap that is essential to the.operation of oscillatorycircuits, such as is herein shown, also thateach of such gaps may be lengthened or shortened to increase, o r todiminish the dielectric resistance of the spark gap, to the passage Y ofcurrent thereacross as may be desired,

further,'that adjustment of said electrodes maybe made by any desiredmeans suitable to the end sought. The electrodes 26, 27 and 28, andu32,33 and 34:, may be madeof any desirable material and in any desired formtype, that will meet and fulfil the conditions that mus t,absolutelyiobtain in each thereof, that is to say, having a body portionprovided with projecting points,

which body and points shall tors of electricity.

' For the. purposes of the present invention, I provide that theelectrodes noted shall each consist of a plate 38,1provided upon oneofits edges with a series of projections 39, and upon its opposite edgewith a screw threaded rod 40, which rod is securely connected to thebody portion 38, and extends thence in suitable supports hereinafter".15 noted The transmitting or sonorous circuit C, comprises thesecondary 41, of the air core transformer H, and the antenna 42, inwhich latter for the purposes of the present invention, I includecurrent interrupting .mechanism, which in the present instance, consistsin a rotatable plate 43, mounted upon a shaft 44, which is provided witha pulley 45, to be turned by a belt 46, from any desired source ofpower, and I provide said plate with stud-s 47 which, extending throughsaid plate project from the opposite sides thereof and are arranged topass through a gap 48, formed in the antenna 42, to close circuittherethrough, when the plate 43 is rotated. It will be understood thatthe plate 43, is to-be made of a suitable non-conducting material, alsothat the studs 47, which extend through and from the opposite sides ofsaid plate, shall be made of a suitable conducting material, and furtherthat such studs shall be so proportioned as to length, that they shallextend nearly into contact with the opposite sides of the gap 48, formedin the antenna 42.

From the arrangement and combination of the several elements comprisedinmy invention as so far described, it-will be understood that currentfrom the generator D, will, because of the peculiar winding of thearmature of said generator and the connec tion thereof with theprimaries 1, 2 and 3, of the respective transformers E, F and G,separately and successively energize said be free conduc- '50 primaries;that theenergizing of said primaries will, in accordancewith the lawwhich obtains in the production of induced currents and which is asfollows: viz. that the closing of circuit through the primary of aninduction coil, will operate to cause a rise of the magnetic flux in thecore of said coil and thus induce electromotive force in the secondaryof said coil in direction opposite to that of the primary, andcontrawise, that the opening of circuit through the primary will operatein like manner to induce current in the secondary, but/in direction likeunto that of the primary,will operate to successively energize thesecondaries 11, 1.2

and 13, of said transformers E, F and G;

that each of said secondaries, 11, 12 and 13, will in turn transmit thecurrent induced therein, by the primary 11, 12, or 13, peculiar theretoas noted, to the primary 15, of the air coretransformerII, through theseveral elements included in the conductors therebetween, thusenergizing said primary; and that the latter named primary will throughthe operation of the law above set forth, induce a current in thesecondary of said air core transformer H, to energize the sonorouscircuit.

It is to be understood that aside fromthe change of current from lowpotential, to high potential, which is consequent upon the action of thestep up transformers E, F and G, no material change in the current ofelece tricity supplied to the primary 15, of the air core transformer11, would result from the operation of the several devices described,that is to say, the current delivered to the primary, 15, will not bechanged in frequency beyond that denoted by the sum total of thefrequencies of the transformers E, F and G, and inasmuch as such achange of frequency is the end sought by the present invention, and thefact that such end can only be accomplished through the interruption ofthe currentresulting from the operation of the devices hereinbeforedescribed,

and further as such frequency depends upon the time interval of suchinterruptions, it

has been deemed expedient to combine with the devices hereinbeforedescribed, certain other devices hereinafter described, in order thatthe full intent and purpose of the invention might be realized.

To the end named, I provide that the current-produced in the circuit B,through the action of the devices hereinbefore described, shall berapidly interrupted, and to such end I place 'within'the spark gaps,which are formed between the terminal points of the electrodes 26 and32, 27 and 33, and 28 and 34, which are located upon opposite sides ofthe spark gaps noted, current interrupting mechanism, which may consistin independent devices each located between the opposite electrodes 26and 32, 27 and 33, and 2S and 34, or, as is the case in the present instance, in which the terminal points of the several electrodes upon thesame side of the spark gaps, are arranged in a plane common to each andall, of a single member, which, in the present invention, consists in arotatable disk I, constructed of a suitable nonconducting material,which is mounted upon sides of thedisk I,- in supports J, J, which aresecured to a common base K, at opposite sides of the disk I.

I provide the shaft I, with a pulley L, to

a shaft I,'that is journaled, atoppositc be turned by a belt L', fromany desired source of power, (not shown herein) to rotate said disk I. j

points opposite to the apertures 2', which, are.

formed through the disk I, with apertures for the passage of the screwthreaded rods 40, of the multiple electrodes, 26, 27, 28, and 32, 33,34. a

Iprovide that the electrodes noted shall, when in position in' theirsupports, be adjustabletoward and fromjthedisk I, to-

which end I provide the supporting rods 40, of said electrodes, uponeach side of ,the apertures in the supports J, J in which said rods aremounted with screw threaded nuts 49and 50, respectively, by theadjustment of which the said electrodes, may be moved toward and fromthe rotatable disk I, as will be readily understood.

' I preferably form the rotatable disk I, of large diameter, so that a.great number of apertures 2', may be formed therethrough, as

is illustrated in Fig. 9, which shows, in full size, a portion of a diskof which the full diameter is 18 inches, and in which, the apertures i,are formed through the disk, each one half inch distant from theperiphery of said disk, and one twelfth of an inch distant, each fromthe other, so that said disk shall,

"when in position for operation contain a instance about 642, in all.

' While I have, in the last above paragraph, set forth the dimensions ofan interrupting disk, with the number of apertures formed therethrough,which I have in practice, found to give results of high order, I yetlarge number ofapertures z, in the present do not wish to limit myselfto disks of the dimensions noted and having the number of aperturesshown, since results, which I h ve already attained through the use of adisk of the dimensions noted, -may be surpassed by disks of a greater ora less diameter and having a greater, or a less number of aperturesformed therethrough, as for instance,-

a disk, similar to that, of which a portion 1s shown. 1n F 1g. 10, 111which the apertures are formed through the disk on a plurality ofconcentric circles, upon each of which such apertures are preferablyseparated for a distance approximating that shown in Fig. 9, and soarranged, with reference to each other, that the apertures upon eitherof said circles, shall fall upon radial lines that would extend betweenthe apertures formed upon the remaining circles, by which araction. v

In Fig.4, the primaries of the transformrangement the number ofapertures formed through a disk of the diameter hereinbefore noted,would be approximately many times that of the disk first abovedescribed.

Again I do not wish to limit myself to the.

useof but one disk between opposing electrodes, as I have found bypractice, that results of great value follow and are consequent upon theemployment of a plurality ,of disks, placed in axial alinement each withthe other, and rotated in opposite directions, as is indicated by,thearrows s and t, in Fig.

8,,for reasons which will be hereinafterset forth.

It is to be understood'that the inductance coils 20, 21-and 22, areincluded in the circuit which includes the secondaries 11, 12 and 13,

of the transforming, or secondary clrcuit B,

for the purpose of reducing to any desired extent, the normal highfrequeneyof the ap- I paratus hereinbefore described, so as to adapt itto the desired frequency of the antenna, to which end, said inductancesare variable in character.

Figs. 2, 3 and 4, of the drawings, respectively representiii-diagrammatic form, the construction and action of one, or more ofthe devices comprised in my invention andof said Figs. 2 and 3,respectively represent, the one Fig. 2, the manner of winding thearmature of the generator D, which figure shows the A ,scheme ofconnection; the other, Fig. 3, the manner of connecting the primaries ofthe step up transformers, with the armature of the generator,whichfigure shows the Y scheme of connection, which connection ispreferably employed for the reason that it shows -higher efficiency iners E, F, and G, are each represented by small rectangular figures whichare succes sively arranged above and below a line n, 0, common to all ofsaid figures, thus primary 1, is indicated by the first rectangularfigure above the line a, 0, primary 2, by the first figure below saidline, primary 8, by the sec- 1 oud figure above the hue and so onsuccessively, as is indicated by the reference numerals 1, 2 and 8.

In Fig; 4, referred to, I indicate the particular phase current whichenergizes-each of the primaries, by a full line, a lineQco'mposedofdashes and a dotted line respectively, thus the phase by which theprimary 1, is energized is indicatedby a full line 51, the phase bywhich the primary 2, is energized, is indicated by a line 52, composedof dashes and the phase by which the primary 3. is energized, isindicated by a dotted line 54. 4

Byreference to Fig. .4, noted, it will be observed that the full line51, passes successively about the outer end of the rectangular figuremarked 1, both above and below the line n, 0, the dash line 52, aboutthe figare marked 2, and the dotted line '53, around tion of the lines51, 52 and 53, about the rectangular figures 1, 2 and 3, noted,indicatesthe extreme distance to which potential rises ineach of theprimaries represented by said figures, or in other words, thesparkperiod of the secondaries 11, 12 and 13, which are respectivelyenergized by said primaries.

Before describing the operation of my invention, I will briefly outlinethe several phase circuits comprised therein, and the relation of eachof said circuits to the other, using to such end the armature rings 7, 8and 9, to denote such phases.

Proceeding, rings 7 and 8, denote phase 1, rings 8 and 9, denote phase2, and rings 9 and 7, denote phase 3, and of said phases that firstnamed, phase 1, supplies primaries 1 and 2, the circuitstarting at ring7, thence running through conductor 4, t6 and through primary 1, thenceto and through primary 2, and thence to ring 8; phase 2, suppliesprimaries 2 and 3, the circuit starting at ring 8, thence running to andthrough primary 2, thence to and through primary 3. and thence to ring9; phase 3, supplies primaries 3 and 1, the circuit starting at ringthence running to and through primary thence to and through primary 1,and thence to-ring 7.

The operation of my invention is as follows, viz: Let it be assumed thata current 'of desired voltage to energize the step up mature of thegenerator D, is rotated 60.

turns per second and since said armature is, as has been hereinbeforestated, three phase wound and each phase thereof connected to energizeone of the primaries 1, 2 and 3,

of the transformers E, F and G, it follows,

thateach of said primaries will be energized once, each time thearmature is rotated, and that the time period between the energizing ofsaid primaries will be equal, each with the other, so that, whilethefrequency of the current supplied to said primaries is cycles persecond, the result, because of the arrangement of the primaries noted,is as though a frequency of 180 cycles per second was employed inconnection with a single transformer, as will be readily understood.

From the foregoing it will be seen that the current 1nduced 1n thesecondaries 11, 12

"and 13, by the action of the primaries 1, 2

and 3, thereupon, will be of like frequency to that of such primaries,and 1t 18 to be un- 'the primary 15, of the air core transformer H, witha frequency like unto, or approximating that of the secondaries 11, 12and 13, were it not for the/inclusion in said gaps, of the rotatableinterrupter I, by which such low frequency current, is changed into ahigh frequency current before it is impressed upon the primary 15,noted, to energize the same and thercthrough to energize the secondary:1, of the air core transformer H, which secondary is the source ofpower of the transmitting, or sonorous circuit will be understood. 7

Since from the foregoing it will be readily apparent that the change inthe current supplied to the circuit B, by the secondaries 11, 12 and 13,from low frequency to high fre-v quency pulsations, is wholly due to theaction thereupon of the interrupter I, it only remains to explain suchaction of the interrupter, and the principle which obtains in theoperation of the transformer H, to clearly establish the nature of thecurrent which is supplied by the secondary 41, of said transformer H, tothe transmitting, or sonorous circuit, and to such end I will herebriefly outline the principle above referred to, which may be thusstated, viz: A current which begins, which approaches, or whichincreases in strength in the primary, induces .by said movements animpulse, or current in or provides a free passage for the current,

or currents of electricity between the multiple electrodes at oppositesides of the spark gaps, in which said interrupter is placed andoperates, it follows that the rotation of said interrupter will operateto intermittently obstruct, or break such current with a very greatrapidity, and as the current thus interupted, or broken, is that bywhich the primary 15, is energized, it will be at once apparent that thecurrent through said primary will be broken each time said interrupterobstructs, or breaks the current crossing the spark gaps, and that, inaccordance with the principle, or law above set forth as obtaining-inthe production of induced currents, each break, or obstruction ofcurrent through the primary, will induce a high frequency impulse in thesecondary, also that successive impulses in said secondary, will be inopposite directions, according to the rise, or the fall of current inthe Drimary.

It will be understood that the-time constant of the circuit B, beingvery small, the rise and fall of. current at each make -and break of theinterrupter, is of very brief duration and the induced current in thesecondary is consequently of high frequency.

From the foregoing it will be clearly ap parent that a current of highfrequency will beinduced inthe secondary of the air core transformer H,through the action of the interrupter I, and further that such highfrequency current, is consequent upon and wholly determined by thenumber of breaks made in the current which is so acted upon, by saidinterrupter, toproduce the high frequency current noted.

I have found by practice, that currents of very high tension andyielding large sparks, may be readily broken up by the employ ment oftwo interrupting disks I, arranged in axial alincment each with theother, and rotated in opposite directions with each other, and thatconsequently the arrangement here noted, is peculiarly applicable incases Where, for any reason, currents of the character above noted, areto be used and broken up.

In Figs. instance Fig. 7 a portion of a single inter.- rupting disk I,placed and moving in the direction of the arrow 7", between opposingmultiple electrodes, and in the latter named Fig.8, a portion of each oftwo disks arranged in axial alinement with each other and movingrespectively in the directions indicated by the arrows s and t, betweenopposing multiple point electrodes, and in each i of said Figs. 7 and 8,I have indicated by dotted lines, the appearance presented by theinterrupted current under the action of 'the disk and disks, in eachinstance -a stream of sparks follow the disks upon each side of eachthereof, in the plane of the aperturesformed thcrethrough, for adistance which,

apparently is determined solely by the rate of speed at which said disksmove.

In .Figs. 11, 12 and 13, I have shown peculiarly formed coils, which,whilefparticularly designedfor use in connection with wireless systemsof transmission, are yet,

' all intents and purposes transformers, in

that they meet and fulfil the conditions which obtain in transformers ofordinary construction.

The coils noted, are named in the order in which they are shown, as abipolar res'on-I ator, a unipolar resonator, and a tuning V coil, and itis to be understood that that part of each of said coils, which isembraced 7 and 8, I have shown, in the one between the points a and a,at which the 12 and 18, are included, and the direct connection of thesame, by'a single wire to, with the antenna, in which form, as-will beobserved, the return conductor 14,- and primary 15, of the transformerH, which are included in the circuit B, as illustrated in Fig. 1, doesnot appear,

VVhileI have herein shown my preferred embodiment of my invention, Ivyetdo not desire to confine myself solely to the particular arrangement andcombination of parts set forth in such embodiment, since differentarrangements thereof might be devised and made, for the purpose ofattaining the end sought by this invention, which end is theproductionof continuous high frequency oscillations in the secondary of an aircore transformer, and I therefore claim the right to-make any and everymodification of this-present invent-ion, {hat shall properly fall-withinits scope and imit. 4'

and combination Having thus described -my 'IIIVfiIllZlOIl I claim anddesire to secure by Letters Patent,

1. In a system for producing electrical oscillations of high frequencyan oscillatory circuit including the secondaries'of a pluralityof stepup transformers and the primary ofan air cpl'etransfermer, a spark gapincluded infthe circuit between each of said step uptransformerswandsaid air core transformer, a source of electrical en;

- crgy for successively energizing each of said cludcd. in the circuitbetween each of said step up transformers and the air core trans former,multlple electrodes 1n each of Sgi'd circuits at each sideof the sparkgaps included in said circuits, means comprlsing an apertured devicecommon-to' each of the spark gaps for continuously interrupting thecurrent crossing said gaps between the multiple electrodes at each sidethereof,

and means for rapidly" moving said apertured device to interrupt thecurrent crossing said spark gaps;

3. In a system for producing electrical oscillations of high frequency athree phase generator, a plurality of step up transformers to besuccessively energized each by a single phase of said generator, acondenser in circuit with'each of' said step up transformers to becharged by said generator, a spark gap in series with each of said condensers, a single air core. transformer common to and having-its primaryin circuit with each of the secondaries of the 'step up transformers, amovable dielectric'device having apertures formed therethrough tosuccessively pass through each of the spark gaps, and means to rapidlyand continu ously move saiddevice tointerrupt current crossing the gaps.

fi. A three phase generator, independent step up transformers eachhavingits primary energized by one phase of current from said generator,an air core transformer having its primary in circuit with thesecondaries of the step up transformers, a condenser in each of thecircuits between the air core transformer and the secondaries of thestep up transformers, a spark gap ,in each "of said circuits in serieswith the condenser therein, a movable device common to each of the sparkgaps in the circuits and provided with apertures, and means to'rapidlyvmove said device to continuously interrupt the current crossing thespark gaps.

5 A three phase generator, independent step up transformers eachconnected to be energized by a single phase of said generator, an aircore transformer having its primary in circuit with the secondaries ofsaid step up transformers, a rotatable apertured disk common to andincluded in the circuit between each of thesecondaries of the step uptransformer and the primary of the air core transformer, and means torotate said apertured disk to continuously in terrupt the currentbetween said step up transformers and said air core transformer.

6. A three phase generator, independent step up transformers eachconnected to be energized by a single phase of said genera tor, an aircore transformer having its priniary in circuit with the secondaries ofsaid step up transformers, a spark gap included in each circuit betweenthe step up transformers and the air core transformer, a to tatableapertured disk common to eaohof said spark'gaps and means to rapidly totate saiddisk to continuously and rapidlyinterrupt the current crossigaps.

* said spark step up transformers each connected to be energized by aslngle phase of sald gen 7 A three phase generator, independent'erator,.an air core transformer having its primary in circuit with thesecondaries of said step up transformers, a condenser in cluded in thecircuit between each step up transformer and the air core transformerand connected to be energized by conduction and induction, a spark gapincluded in each of said circuits in series with the condenser therein,a rotatable apertured disk common to each of said spark gaps, and meansto rapidly rotate said disk to continuously interrupt the currentbetween the step up transformers and the air core transformer.

8. A three phase generator, independent step up transformers .eachconnected to be energized by a single phase of said generator, an aircore transformer having its primarvin circuit with the secondary of eachof the step up transformers, a condenser included in the circuit betweeneach step up transformer and the air core transformer, a spark gapincluded in each of said circuits in series with the condenser therein,a plurality of oppositely moving disks arranged in parallel planes andcommon to all the.

spark gaps each of said disks having apertures to be brought intoa-linement with the apertures of the other disk, and means to rapidlyrotate said disks in oppositedirections'to successively move theapertures of said disks into alinement to continuously ing spark gapsformed therein between each of said secondaries of the step uptransformers and the primary of the air core transformer, a rotatabledisk of non-conducting material having apertures formed therethroughequidistant from the axis of said disk. and said disk connected to bemoved in the gaps formed in the circuit, means connected to bring theapertures of the disk into alinement with the electrodes of each circuitto close circuit through the apertures and means to rapidly rotate saiddisk to produce a high frequency current in the secondary of the aircore tri'insformcr.

10. The combination in apparatus for producing high frequencyoscillations of a three phase generator, independent step uptransformers each having its primary energized by one phase=of saidgenerator, an airnectedto energize the primary in series with each ofsaid spark gaps, a multiple electrode upon each of the conductors'comprised in the circuit at each side of the spark gaps, an interruptercomprisingan apertured rotatable disk to move in the spark gaps betweenthe multiple electrodes, and means to rotate said disk to rapidly andcontinuously interrilp current across the gaps between the multipleelectrodes.

11. In a system for producing and trans-I mitting electricaloscillations a generating circuit including a three phase generator andthe primary of a step up transformer in circuit with each phase of saidgenerator, an oscillatory circuit, including the second ary of each ofsaid step uptransformers the primary of" aniair core transformer in.cluding the secondary of the air core transformer the transmittingantenna and an interrupting device interposed in said antenna. 12. In a.system for producing electrical oscillations of high frequency aplurality ofprimary circuitseach thereof including the primary ofconnected to be energized by one phase of a polyphase current generatorof electricity commonto each of said circuits, a plurality ofsecondarycircuits each thereof including the secondary of a step up transformer aspark gap and a condenser interposed between and in series with saidsecondary and said spark gap and each of said circuits coni of an aircoretransformer common to each of said circuits, and a currentinterrupting device common to each of the spark gaps of the secondarycircuits and connected to interpose in succession solid dielectricmediums moving at a rapid predetermined speed and at equal intervals oftime between the opposite poles of each of said spark gaps to interruptcurrent passing thereacross;

13. In a system for producing and transmitting electrical oscillationsof high frequency a pin 'ality of primary circuits eachthereof includingthe primary of .a step up transformer and connected to be energized byone phase of a polyphase current generator of electricity common to eachof said a step up transformer and primary of an air core transformercommon to each of said circuits, a current interrupting device common toeach of the spark gaps of the secondary circuits and connected tointerpose successive solid dielectric mediums moving ata predeterminedspeed and at equal intervals of time between the opposite poles of eachof said spark gaps to interrupt current passing thereacross, and atransmittingcircuit including the secondary of an air core transformertransmitting antenna and current interrupting devices interposed in saidantenna.

14:. In a system for producing and transmitting electrical oscillationsof high frequency a plurality of primary circuits each thereof includingthe primary of a step up transformer and connected to be energized byone phase of a polyphase curent generator of electricity common to eachof said circuits, a plurality of secondary circuits. each thereofincluding the secondary of a step up transformer and a condenser inseries with said secondary and each of said circuits connected toenergize the primary of an air core transformer common to each 'of saidcircuits, a spark gap included in each of said secondary circuits inseries with the condenser therein and having each of its oppositeelectrodes provided with a plurality of terminal points to project intoproximity to a current interrupting device placed to move in said'spark' gaps, a current interrupting device common to each of the sparkgaps and connected to interpose successive portions of a soliddielectric medium between the terminal points of the opposite looelectrodes of each of the spark gaps at a high speed and at equalintervals of time to interrupt current passing thereacross, and

a transmitting circuit including the secondary of an aircore'transformer transmitting antenna and current interrupting devicesinterposed in said antenna.

" In testimony whereof, I hereto affix my,

signature in presence of two witnesses.

v DAVID G. MCCAA. Witnesses:

MARTIN E. Mussna, W. G. WADE.

gap and a con- -60

